Embossed non-woven fabric having a three-dimensional structure

ABSTRACT

A three-dimensionally embossed non-woven fabric, which is comprised of fibers and/or filaments ( 3 ) oriented primarily in the moving direction ( 2 ) of the machine, and has zones ( 5, 7 ) with regularly alternating elevations ( 4   a   , 8   a ) and indentations ( 4   b   , 8   b ), which are separated from one another by non-embossed areas ( 6 ) that are continuous in the moving direction ( 2 ) of the machine. These non-embossed areas constitute a proportion ranging from 5% to 50% with regard to the entire surface of the non-woven fabric ( 1 ) and the elevations ( 4   a   , 8   a ), and indentations ( 4   b   , 8   b ), when viewed from the opposite side, form indentations or elevations respectively, whereby the surfaces ( 10   a   , 10   b ) delimited by the elevations give the non-woven fabric an apparent thickness ranging from 0.5 mm to 5.5 mm.

The present invention relates to an embossed, open-pore non-woven fabrichaving a three-dimensional structure, a method for its manufacture and adevice used with it. The non-woven fabric is made up of regularlyalternating areas having molded, weight-thinned three-dimensionalelevations and non-molded, flat zones having an unchanged weight.

The present invention also relates to a special embossing method and theroller geometry required for it in order to impart the special 3Dembossed structure to the non-woven fabric after its passage through thepress gap of two engaged positive and negative rollers.

The absorbent core of infant diapers, incontinence and feminine hygieneproducts is today covered by at least two layers on the side worn nextto the body. Between the cover non-woven fabric or the perforated filmand the absorbent core is positioned an acquisition and distributionlayer (ADL) of non-woven fabric or reticulated foam, which as the nameimplies, quickly takes up the body fluid (urine, thin feces or menses)and distributes it as uniformly as possible to the absorbent core lyingunder it, which is normally made of cellulose and super absorbentpowder. This keeps the human skin dry, thus preventing skin irritationas well as leakage of the body fluid at the sides. The back of theabsorbent hygiene product is sealed against permeation of body fluid bya watertight film or a non-woven-film laminate.

Non-woven fabrics bonded thermally in a hot air dryer or non-wovenfabrics of crimped, relatively coarse denier fibers bonded by polymerdispersions are known for use in ADLs. The fibers have deniers greaterthan 3.3 dtex and are made up primarily of polyester (polyethyleneterephthalate) and/or polyolefins, bicomponent fibers having aside-by-side or a core/jacket structure being used for fiber bonding inthe through-flow oven and one of the two fiber components being meltedsignificantly more deeply than the other component. In relation to theirlow weight, such non-woven fabrics have a relatively high bulk(thickness). It is known, however, that this initial thickness isalready significantly reduced when the product is rolled up understresses ordinarily used and the pressure conditions in the packagingcontribute further to the reduction in thickness.

For that reason, means have been sought to achieve a thickness not onlyby using crimped fibers having a more or less statistical distributionand their bonding but also to bring such crimped non-woven fabrics intothe third dimension, which we will consistently describe as theZ-direction in the following, by undulation or other geometricorientations. It has been shown that this makes it possible to attainhigher compression resistances than by using high-loft non-woven fabricswith the consequence of significantly reduced loss of thickness when adiaper passes through the production steps, including packaging andstorage.

An embossing method for manufacturing a structured, bulky non-wovenfabric is described in DE 197 25 749 A1. A pre-bonded spun non-wovenfabric, the endless filaments of which have been drawn to only 50% to70% of the maximum possible draw ratio, are subjected to a particularfinishing treatment. In doing so, the spun non-woven fabric is passedbetween a positive roller having a knobby surface and a negative rollerhaving lamellar strips positioned transverse to the machine direction,the strips meshing with the channels kept open by the knobs. Thisresults in 3D non-woven fabrics having areas of conically shapedweight-thinned elevations that are surrounded by linear, undeformedareas.

The disadvantage of the embossing method described in DE 197 25 749 A1is that it is limited to undrawn or partially drawn endless filamentnon-woven fabrics (spun non-woven fabrics). Such non-woven fabrics aremade from coarse-denier, uncrimped endless fibers that are known toresult in hard, rough and non-textile products and therefore are notused as ADLs in diapers. Such endless filaments having a side-by-sidestructure or an asymmetric core/jacket structure do not result incrimping in a partially drawn state. Such crimping is ordinarilytriggered by subsequent thermal processing, which in turn—as is known tothose skilled in the art—prevents drawability (or formability) due tothe crystallization which has occurred. Consequently, the prerequisitesfor the applicability of the embossing method described in DE 197 25 749A1 are lacking.

A fluid distribution material having improved fluid distributionproperties is described in EP-B 0.809.991 and EP-A 0.810.078. In thiscase, a plastically deformable web is formed into a non-woven fabrichaving a 3D structure by passing it through a pair of negative/positiverollers. A variation of the two applications referenced above is theembossed material and method for it, which is described in EP-B0.499.942. However, such structures similar to corrugated cardboard havethe disadvantage that they do not withstand any sustained pressureloads.

In EP applications 1.047.824, 1.047.823, 1.047.822 and 1.047.821,non-woven fabrics having elevations and indentations are produced in anintermediate step by passing the sheet material over two heated toothedgear rollers. The ribbings have little compression stability based onthe fact that they lack a non-stabilizing fabric, which is glued to oneside of the elevations or stiffenings. In the patent applications cited,it is rather the case that the undulations must be removed to thegreatest possible extent or partially removed to produce soft andslightly elastic products transverse to the undulation.

Absorbent disposable items having a fecal management layer are knownfrom EP-A 0.976.375, EP-A 0.976.374 and EP-A 0.976.373, the latter beingmade from an undulated non-woven fabric to which a flat non-woven fabricbacking (EP-A 0.976.375) is cemented. Thick polymer filaments (EP-A0.976.374) or meshed fabrics (EP-A 0.976.37) may be used instead of thenon-woven fabric backing. Such undulated non-woven fabric laminatesstabilized by a backing have proven to be suitable ADLs for fecalmanagement and improved urine management. However, the production ofsuch 3D laminate structures is very elaborate and requires twocomponents and an additional adhesive in many cases. However, the use ofa thick monofilament (having a denier in the range of several thousanddtex) proved to be unsuitable because such monofilaments are undrawn (orcome from a hole-type nozzle) and therefore stretch under the strongmechanical load in the machine direction in diaper production withthinning of the filament and thus have an unacceptable property in thisrespect.

The object of the present invention is to eliminate the aforementioneddisadvantages of the related art and to provide an embossed non-wovenfabric, which returns to its original shape after a previous compressionbetter than the previously known embodiments without the requirement ofan additional stabilizing layer, and is consequently better suited forthe uptake of liquids of varying composition or the transport of theliquids into an absorbent layer. The object of the present invention isfurthermore to provide a method for manufacturing a non-woven fabric anda device suitable for implementing the method. In particular, anembossing device is to be offered to diaper manufacturers as an additionto a diaper production line, the device permitting the manufacturer toconvert an unembossed, two-dimensional non-woven fabric inline with thediaper production into the form of an embossed, three-dimensionalnon-woven fabric having an improved liquid acquisition and distributionfunction and to place it in a diaper or a wound dressing. Moreover, itshould be possible to produce the non-woven fabric independently of thediaper production, and the non-woven fabric should have theaforementioned properties largely unchanged after an intermediatestorage in rolled-up condition.

According to the present invention, the three-dimensionally embossednon-woven fabric is made up of fibers and/or filaments 3 oriented inmachine direction 2 and zones 5, 7 having regularly alternatingelevations 4 a, 8 a and indentations 4 b, 8 b, which are separated fromone another by unembossed, continuous areas 6 in machine direction 2,the unembossed areas making up a proportion ranging from 5% to 50% inrelation to the entire surface of non-woven fabric 1 and elevations 4 a,8 a and indentations 4 b, 8 b, when viewed from the opposite side,forming indentations and elevations, respectively, the surfaces definedby the elevations imparting an apparent thickness ranging from 0.5 mm to5.5 mm to the non-woven fabric.

Additional advantageous embodiments are described in the subclaims.

The present invention describes a non-woven fabric of staple fibers inwhich partial surface areas have regularly alternating elevations andindentations (peaks/valleys) in the machine direction and each row ofelevations/indentations is interrupted by an unshaped linear area. Theunshaped linear areas are positioned symmetrically to asymmetrically tothe elevations and valleys of the adjacent areas in thethree-dimensionally formed non-woven fabric. In a preferred embodiment,the areas formed into peaks and valleys extend symmetrically along theunshaped linear area.

The row of adjacent formed areas transverse to the machine direction issituated in such a way that there is always a gap to the adjacent row ofundulations.

The undulations extend exactly in the machine direction.

The method of the present invention for manufacturing a non-woven fabricis such that fibers and/or filaments 3 oriented primarily in machinedirection 2 are laid down on a gauze, reinforced and formed into athree-dimensional non-woven fabric by a treatment using embossingrollers at temperatures ranging from 65° C. to 160° C.

Additional advantageous embodiments of the method are described in thesubclaims.

The staple fibers of the two-dimensional non-woven fabric for the 3Dembossing are laid down in the machine direction. The fiber gauze may beadditionally reoriented along this preferred direction using acompression device.

The staple fibers of the staple fiber gauze laid down in the machinedirection are crimped two-dimensionally and/or three-dimensionally.

The fibers are made from fiber polymers that have a high restoring forcein relation to mechanical forces. Polyethylene terephthalate fibershaving a denier ranging from 3.3 to 30 dtex, preferably however, 6.7 to18 dtex have proven to be suitable in particular. Fibers of differentdeniers may be blended.

The staple fiber gauzes are either bonded adhesively by using aqueouspolymer dispersions according to known methods, by thermal fiber/fiberbonding in a forced air oven, or by application of heat and pressure ina pair of calender rolls. In the case of passage through a forced airoven, bicomponent fibers are added to the homophilic fibers as bindingfibers.

The non-woven fabric presented for embossing contains a hydrophilic,easy-to-wet surface-active agent (surfactant), which is either appliedinto or on the fiber by the fiber manufacturer and/or is applied to thenon-woven fabric later and/or is introduced into the non-woven fabricwith the polymer dispersion preparation used. The surfactant may have avarying degree of bonding to the fibers and may thus be removable bywashing or semi-permanent to completely permanent against the contact ofbody fluid.

In the case of an adhesive bond, an aqueous polymer dispersion based ona butadiene copolymer such as styrene-butadiene oracrylonitrile-butadiene copolymer is used. The binding agent ispreferably free from cross-linking components and after applicationremains in the non-woven fabric in a thermoplastically deformablecondition. The Shore hardness A of the binder film cast from thedispersion is in the range of approximately 70-100, preferably 75-95.

The cross-section of the staple fibers may have varying forms such asround, oval, trilobal, square, rectangular. The fiber polymer may bedistributed over the entire fiber cross-section in the same thickness.However, the fiber may also be internally hollow, it being possible forthe hollow space to make up 10%-30% of the fiber.

All crimped single component synthetic fibers that do not shrink or evenmelt under the embossing conditions are suitable for the embossingmethod of the present invention. The crimped synthetic fibers may alsobe blended with undrawn, uncrimped fibers, however, at a proportion<50%.

The base material to be formed into a 3D structure preferably containspolyester fibers if an aqueous dispersion is used for the non-wovenfabric bonding. The fiber: binder ratio is approximately 20:80 to 40:60.The binding agent may be applied using known application methods such asfoam impregnation, one-sided slop padding or wet-in-wet printing. Thebinding agent may be uniformly distributed over the cross-section of thenon-woven fabric or it may have a binding agent applied quantitygradient from one side to the other. The drying temperatures andretention times in the dryer must be selected in such a way that acomplete filming of the polymer takes place. This may be determined bythe transparency (of the unpigmented binder agent) of the bindingpoints.

The staple fiber gauze of the precursor may be made up of one or as manyas three plies. The average denier of the three plies preferablyincreases from one ply to the next adjacent ply. After the 3D formation,the multi-ply non-woven fabric having the coarsest (highest denier)gauze side is positioned in the diaper as an ADL facing the underside ofthe non-woven cover fabric. In the case of an embossed non-woven fabrichaving binding agent distribution gradients, the side having morebinding agent is in contact with the absorbent core or with thehydrophilic meltblown non-woven fabric or tissue paper (core wrap)enveloping it.

The device of the present invention for implementing the method includesat least two embossing rollers 21, 22, which mesh in such a way that anon-woven fabric 20 is guided between them and formed, embossing rollers21, 22 being made up of toothed wheels 11, separated by spacers 12 on ashaft 13.

Additional advantageous embodiments of the device are described in thesubclaims.

The present invention will be described in greater detail with referenceto 6 figures.

FIG. 1 shows a top view of a three-dimensional non-woven fabric formedaccording to the present invention

FIG. 2 shows the cross-section of a three-dimensionally formed non-wovenfabric formed according to the present invention along section line 9-9

FIG. 3 shows the cross-section of a three-dimensionally formed non-wovenfabric formed according to the present invention along section line27-27

FIG. 4 shows a schematic representation of an embossing roller

FIG. 5 shows the cross-section through an embossing roller

FIG. 6 shows a schematic representation of a device according to thepresent invention

FIG. 7 shows a cross-section of a toothed wheel disk

A top view of the 3D embossed non-woven fabric 1 is shown in FIG. 1.Arrow 2 indicates the machine direction. The non-woven fabric is made upof fibers 3 oriented in machine direction 2, which are bonded togetherby known methods. In machine direction 2, non-woven fabric 1 has twocontinuously repeating zones 5, 7 and area 6, zones 5 and 7 having a 3Dembossing and area 6 positioned between zones 5 and 7 remaining in theunembossed condition. Elevations 4 a of zones 5 alternate withindentations (valleys) 4 b. Within zones 7, elevations 8 a andindentations 8 b are situated in such a way that there is, for example,a gap between them and elevations 4 a and indentations 4 b of zones 5.Non-woven fabric 1 thus includes two surfaces, the elevations formingone surface and the indentations forming the other one. FIG. 2 shows asection along line A-A and the view of this section transverse tomachine direction 2. The undulated 3D structure formed by consecutivearc-shaped elevations 4 a and indentations 4 b is shown in theforeground. Behind these undulations, unembossed areas 6 extend inmachine direction 2. A second wavy line, which is indicated byelevations 8 a and valleys 8 b, extends behind areas 6. There is a gapbetween 8 a and 8 b and 4 a and 4 b, respectively.

FIG. 3 shows the section along line B-B (i.e., transverse to machinedirection 2) as the foreground and the view in machine direction 2 asthe background (dashed lines). The mass per unit area of unmolded areas6 is significantly higher than the mass of adjacent zones 5 and 7. Themass per unit area of 3D embossed zones 5 and 7 is reduced by the factorobtained by dividing distance 28 by the perimeter from point 29 to point30. If, for example, the mass per unit area of the unembossed non-wovenfabric is 60 g/m², distance 28 has a length of 6 mm and the perimeterfrom point 29 to 30 has a length of 15 mm, the weight for the 3Dembossed zones along its surfaces is 24 g/m², corresponding to asignificant thinning of material by 60% fiber mass within the embossedzones. The higher mass per unit area in zones 6 in conjunction with theundamaged fiber bonds at that location gives rise to the advantageousproperty of the non-woven fabric that, without requiring an additionalstabilizing layer, it generally returns to its original shape after apreceding compression better than all previously known designs with theconsequence that the non-woven fabric is better suited for theacquisition of fluids of varying composition or the transport of thefluids into an absorbent layer.

An embossing roller 21 is shown in FIG. 4. A toothed wheel disk 11 andan untoothed spacer disk 12 having a smaller diameter are placed inalternation on a shaft 13 provided with a clamping wedge 14.

The diameter of disk 12 corresponds to the diameter of toothed wheeldisk 11 at its deepest points 17 (the valleys).

A cross-section of such an embossing roller 21 is shown in FIG. 5. Teeth15 of front toothed wheel disk 11 have elevations 16 and indentations17. An untoothed disk 12 having diameter 19 is placed on shaft 13including its groove 18 (not visible) behind toothed wheel disk 11.

According to FIG. 6, an embossing unit is made up of at least twomeshing embossing rollers 21 and 22. At least one of the two isheatable. A heat source 26 may additionally be installed to heat theroller surface. Unembossed non-woven fabric web 20 passes the meshingteeth of both embossing rollers 21 and 22 in area 23 and is molded,favored by heat, into a 3D embossed non-woven fabric of the novelsurface structure. Delivery roller 24 has a rough surface 25, whichfavors the further transport of the sheet product.

The embossing device may be operated at a maximum width of approximately220 cm. In a narrower embodiment having roller widths betweenapproximately 55 cm to 125 cm, preferably between 65 cm and 90 cm, itmay be integrated into diaper machines. This is a particular embodimentof the method, which has the advantage of delivering flat roll productscut into discs and eliminating the logistic problem of placing the tapesinto cartons (festooning) or cost-intensive, crosswise winding(spooling).

The method according to the present invention, including the specialembodiment of embossing in the diaper machine, has the further advantagethat the unembossed non-woven fabric having a fluid acquisition anddistribution function may be more strongly compressed than one notsubjected to 3D embossing. An unembossed rolled product always has theproblem that stronger thickness compression takes place in the roll corein the vicinity of the core than in the outer area, which is notcompletely equalized even after placement in the diaper. A master rollhaving a 3 inch core as an inner diameter, having bonded acquisition anddistribution non-woven fabric wound on an outer diameter of 114 cmresults in approximately 2,500 to 3,000 linear meters per roll. A lowerwinding tightness might solve the compression problem in the windingcore to a great extent; however, this is associated with the costdisadvantage of fewer linear meters on the roll. The method according tothe present invention and the embossed, bulky finished materialresulting from it permits a significantly stronger compression of theunembossed semifinished material having the advantage of eliminating thementioned compression problem in the winding core and the logisticaladvantage of obtaining significantly more linear meters of length on thewinding.

The unembossed non-woven fabric in the weight range from 30 to 100 g/m²,preferably 40 to 80 g/m², has a thickness of 0.20 mm to 1.50 mm,preferably 0.35 mm to 1.20 mm, measured at a load of 0.5 kPA. Thethickness after embossing is primarily a function of the height of theteeth, the distance between the teeth (degree of engagement=intensity ofthe meshing) and secondarily of the mass per unit area of the unembossednon-woven fabric. The thickness of the embossed non-woven fabric,measured across the intended areas produced by the elevations rangesfrom approximately 0.50 mm to approximately 5.50 mm, preferablyapproximately 0.900 mm through approximately 4.50 mm.

The width of zones 5 and 7 having toothed wheel embossing ranges fromapproximately 3.0 mm to approximately 20 mm, preferably 6 mm to 12 mm.Zones 5 and 7 may each have the same width or they may also have varyingwidths. Preferably, they have the same width. Areas 6 are generally lessthan or equal to half the sum of the width of zone 5 and zone 7 andpreferably amount to only approximately 5% to approximately 25% of thissum. If, for example, a width of 7.0 mm is selected for zone 5 and 7,the width of areas 6 is only 0.7 mm to 3.5 mm. Areas 6 may have varyingwidths; however, they may not exceed a maximum total area of 50% andpreferably range from approximately 10% to approximately 33%, relativeto the total area of the embossed non-woven fabric. However, a 3D visualappearance having areas 6 of equal width is preferred in particular.

Hydrophilic binding agents (or those made absorbent by the addition ofwetting agents) may be applied to the underside of the 3D embossednon-woven fabric used as an ADL. The side whose surface is defined byunembossed areas 6 and indentations 4 b and 8 b is understood to be theunderside. Such one-sided application of a binder may be advantageousfor the purpose of further 3D structure stabilization and may support atransport of the fluid in the direction of the absorbent core byincreased hydrophilia.

EXAMPLE 1

A gauze of crimped polyester staple fibers having a denier of 6.7 dtexand a cut length of 51 mm is laid down in the machine direction. Thegauze weight amounts to 45 g/m². The gauze is wetted with water in orderto make the subsequent one-sided printing with binding agent easier. Anaqueous polymer dispersion based on carboxylated styrene butadienecopolymer is used as a binding agent. The Shore hardness A of the filmproduced from this binding agent is approximately 90 to 95. A wettingagent, some pigment dye and dilution water are added to the 50%dispersion resulting in a “water-thinned” 40% mixture. This mixture isapplied to one side of the fiber gauze using an anilox roll, theindentations of which are filled with this mixture. During drying ondrying cylinders at 180° C., the binding agent partially migrates towardthe side free from the application of binding agent. This results in aconcentration gradient of the binding agent from one side of thenon-woven fabric to the other. After drying, the product stays on thedryer until the binding points have been totally filmed. This relativelyhard carboxylated styrene butadiene latex is applied in the amount of 15g/m². This results in a fiber: binder ratio of 75:25.

The properties (thickness, repetition and the like) of this unembossedproduct are compared to those of an embossed product in Table 1.

This semifinished product was then subjected to embossing according tothe present invention, an embossing device corresponding to FIGS. 4through 6 having been used.

The enlarged cross-section of a toothed wheel disk is shown in FIG. 7.r_(i) is understood to be the internal radius of the toothed wheel andr_(a) the external radius of the toothed wheel. Height h of the teeth iscalculated as the difference between r_(a) and r_(i). The (curved)distance ti on the inside and ta on the outside may be calculated fromthe formula for circumference u=2rπ. Circumferences u_(a) and u_(i) maybe calculated by multiplying the number of teeth z on the toothed wheelhaving the pitch t_(i) and t_(a), respectively:u _(a) =zt _(a) and u _(i) =zt _(i).

In examples 1, 2, embossing rollers having toothed wheels of thefollowing dimensions and shape are used:

-   Z=28-   r_(i)=35 mm-   r_(a)=37.5 mm

The following values for t_(i) and t_(a) are calculated using the abovemathematical relationships: t_(i)=7.85 mm and t_(a)=8.41 mm

As a result of the tapering of the teeth toward the outside of theroller and the circular diameter of the roller, the followingrelationship applies to distances d_(i) and d_(a).

-   d_(a)>d_(i)

In Example 1, the ratio of d_(a):d_(i) amounts to 2.88:1.0.

The width of spacer 12 (see FIG. 4) is 0.20 mm and the width of thetoothed wheels is 0.75 mm, as a result of which unembossed area 6amounts to approximately 20% of the total area of the non-woven fabric.

Non-woven fabric 20 weighing 60 g/m² is guided through the gap betweenthe two meshing embossing rollers 21 and 22 at a speed of 10 m/min. (600m/hr.). The external temperature of toothed wheel roller 11 made of SAE1045 steel is 125° C. Toothed wheel roller 22 made of polyamide isunheated and heats up somewhat during the run. Additional heat source 26ensures that the temperature on the steel roller drops. Delivery roller24 is cooled. Subsequently, the product is rolled up with as littletensile stress as possible.

EXAMPLE 2

The procedure is the same as in Example 1 except that the gauze weightis reduced to 31 g/m². The binding agent is applied in the amount of 12g/m², which corresponds to a fiber: binder ratio of approximately 73:27.

The 3D embossing is performed as in Example 1.

COMPARATIVE EXAMPLE 1

The binder-bonded non-woven fabric manufactured in FIG. 1 weighing 60g/m² is subjected to embossing according to the related art. To thisend, a roller pair is manufactured without having spacer disks 12 placedon the cone between the toothed wheel disks and in which all the toothedwheel disks have the same position, i.e., they are not turned to have agap. The tooth depth is selected as in Example 1.

The binder-bonded non-woven fabric weighing 60 g/m² manufactured in FIG.1 is embossed under the conditions of Example 1.

This conventionally embossed reference pattern having a type ofundulation corresponding roughly to that of corrugated cardboard ischecked for thickness, recovery capacity and creep resistance. Theresults of the reference pattern, of the unembossed semifinished productand the pattern of Example 1 are compared in Table 1.

Testing Methods Applied

-   -   Liquid strike-through time according to EDANA 150.3-96 (Lister        tester)    -   Coverstock rewet (also known as wet back) according to EDANA        151.1-96

Strike-through times were measured after the 1^(st), 2^(nd) and 3^(rd)application of fluid and the rewet after the 3^(rd) application offluid.

The results of Examples 1 and 2 of the unembossed and the embossedbinder-bound non-woven fabric as arithmetic means from three singlemeasurements each are compiled in Table 1. TABLE 1 Liquid strike-throughand rewet measured directly on the test object (outside of the diaper)according to the EDANA method and using the Lister test apparatus Liquidstrike-through time(s) after 1^(st), 2^(nd), and 3^(rd) application offluid Rewet Test object 1 time 2 times 3 times (g) Example 1 unembossed0.91 1.92 2.21 0.07 Example 1 embossed 0.04 0.01 0.10 0.06 Example 2unembossed 0.03 0.69 0.94 0.08 Example 2 embossed 0.00 0.02 0.02 0.04

The results shown in Table 1 make it clear that the liquidstrike-through time in particular of the embossed non-woven fabric ofthe present invention is significantly lower (better) than in theunembossed condition. In the case of rewet as well, improvements arenoted that turn out, however, to be less significant than for the liquidstrike-through time. In the Kanga test, performed on one diaper (seeTable 2), the rewet results are, however, significantly better than forthe EDANA-Lister test.

-   -   Liquid strike-through time using the Kanga test of Stockhausen        S.OSSE.204-3.0, measured on one diaper:

A commercially available maxi plus size diaper without an acquisitionand distribution layer is opened and the test object is placed betweenthe absorbent core and the top sheet as an acquisition and distributionlayer. The diaper is then reclosed and subjected to the Kanga test inthis manner. 120 ml of a 0.90% saline solution per sample (syntheticurine) is used as a test liquid. After the diaper is centered betweenthe round (corresponding to body shape) plastic body and the fabric tapesurrounding it, the plastic body is loaded using a weight of 12.5 kg.Subsequently, 120 ml of the liquid is poured into the perpendicularlyoriented (for girl, unisex) cylinder of the test apparatus and the timeuntil the liquid is totally soaked into the diaper is measured(strike-through time 1).

After an approximately 20 minute waiting time, a second (strike-throughtime 2) and a third measurement (strike-through time 3) are performedusing the same quantity of liquid (120 ml).

Rewet using the Kanga test of Stockhausen S.OSSE.204-3.0, measured onone diaper:

To determine the rewet properties, after the third quantity of liquid istotally soaked in and an additional waiting time of 20 minutes, thediaper is removed from the measuring apparatus and spread out on atable. A weighed stack of 3 filter papers of approximately 40 g/m² eachis placed on the liquid entry point of the diaper and by 1270 g(corresponding to a pressure load of approximately 20 g/cm²). After 20minutes, the filter paper stack is reweighed. The lower the value, thedryer the baby's skin stays. TABLE 2 Results for strike-through time andrewet determined according to the Kanga method Kanga test Strike-throughtime(s) after 1^(st), 2^(nd), 3^(rd) application of liquid Rewet Maxiplus size diaper 1 time 2 times 3 times (g) Brand name diaper No. 1 -original 13.5 27.5 34.0 37.2 condition Brand name diaper No. 1 - opened11.3 25.5 33.0 31.5 Brand name diaper No. 2 - original 13.5 33.5 43.311.9 condition Brand name diaper No. 2 - opened 14.0 52.3 60.0 0.44Brand name diaper No. 3 - original 22.2 30.3 53.5 16.1 condition Brandname diaper No. 3 - opened 23.1 47.9 65.2 20.9 Diaper having embossedADL 5.3 9.5 12.1 0.28 from Example 1

Table 2 shows that the non-woven fabric of the present inventiondisplays significantly better properties when installed in a diaper asan ADL.

Creep Resistance CR

To determine creep resistance CR, samples sized approximately 7 cm×7 cmwere punched out and maintained at a constant temperature in thelaboratory for 25 hours. Three single measurements were taken in eachcase to determine an arithmetic mean.

A load of 7.2 kPa is placed on the test object for 72 hours at 45° C.The place to be loaded is marked. Subsequently, the sample is removedfrom the oven and unloaded for 2 minutes. The thickness is then measuredat a pressing pressure of 0.5 kPa and a pressing pressure area of 25cm². The thickness was measured again after an unloading time of 2 hoursand 24 hours. TABLE 3 Thickness measurement after thermal storage (creepresistance KB) and after varying unloaded recovery times Initialthickness After 72 hours storage at before 45° C. and 7.2 kPa loading atand a recovery time of 45° C. t = 0 t = 2 hr. t = 24 h hr. mm at mm atmm at mm at Test object 0.5 kPa 0.5 kPa 0.5 kPa 0.5 kPa Example 1unembossed 0.92 0.59 0.63 0.68 Example 1 3D embossed 2.56 0.67 0.72 0.91Reference 1.87 0.51 0.54 0.60

The starting thickness of the reference sample having conventionalembossing (undulation) displays a significantly lower thickness after aloading of 0.5 kPa than Example 1, which is 3D embossed according to themethod of the present invention.

Specific Volume (SV)

Thicknesses d were measured at loads of 0.50 kPa and 6.2 kPa. Thefollowing calculation is used to determine the value for specific volumein cm³/g (the reciprocal value of specific bulk density):SV=(d/FG)×1000 in (cm ³/g)

FG being the mass per unit area of the non-woven fabric in g/m² and dthe thickness in mm. TABLE 4 Specific Volume Specific volume Relativespecific (cm³/g) Volume (%) Test object at 0.5 kPa at 6.2 kPa at 0.5 kPaat 6.2 kPa Example 1 unembossed 15.3 11.6 100 100 Example 1 3D embossed42.6 14.7 278 127

The values shown for specific volume in Table 4 show that an improvednon-woven fabric having a significant fluid acquisition function hasbeen created using the 3D embossing according to the present invention.

1-22. (canceled).
 23. A three-dimensionally embossed non-woven fabrichaving a first side and a second side and a manufacturing machinedirection comprising: fibers and/or filaments; the first and secondsides being provided with zones having regularly or irregularlyalternating elevations and indentations, the zones being transverse tothe machine direction and separated from one another by unembossed,continuous areas extending in the machine direction, the unembossed,continuous areas constituting a proportion ranging from 5% to 50% withrespect to the surface area of the non-woven fabric, the elevations whenviewed in cross-section, being formed by a prolongation on both sides ofthe unembossed, continuous areas.
 24. The fabric as recited in claim 23wherein tops of the elevations and indentations on both sides defineimaginary planes, the imaginary planes having a distance H of 0.5 mm to5.5 mm from one another.
 25. The fabric as recited in claim 23 whereintops of the elevations and indentations on both sides define imaginaryplanes, the imaginary planes having a distance of 0.9 mm to 4.5 mm fromone another.
 26. The fabric as recited in one of claims 1 through 3,wherein the unembossed, continuous areas occupy a proportion of 10% to33% relative to the surface area of the non-woven fabric.
 27. The fabricas recited in claim 23 wherein the fibers or filaments are primarilyoriented in the machine direction.
 28. The fabric as recited in claim 23wherein the elevations and indentations of Page 6 of 10 Attorney DocketNo. 331.1068 adjacent zones are arranged in a grid-like pattern.
 29. Thefabric as recited in claim 23 wherein the elevations and indentations ofadjacent zones are arranged so that the elevations and indentations arearranged symmetrically on both sides of the unembossed, continuousareas.
 30. The fabric as recited in claim 23 wherein the elevations andindentations of adjacent zones have a clearance on both sides of theunembossed, continuous areas, viewed in the machine direction.
 31. Thefabric as recited in claim 23 wherein the elevations and indentations ofadjacent zones are asymmetrically displaced in relation to one anotheron both sides of the continuous areas viewed in the machine direction.32. A method for manufacturing a non-woven fabric as recited in claim 23comprising the steps of: forming a flat non-woven fabric comprised offibers and/or filaments primarily oriented in a manufacturing machinedirection so that the fibers and/or filaments of the non-woven fabricare bonded together; and subsequently subjecting the non-woven fabric tothe action of at least one embossing roller at a temperature rangingfrom 65° C. to 160° C. so as to form a three-dimensional non-wovenfabric.
 33. The method as recited in claim 32 wherein the fibers orfilaments are bonded by a binding agent.
 34. The method as recited inclaim 33 wherein the binding agent is applied to one side of thenon-woven fabric.
 35. The method as recited in claim 33 wherein awetting agent is added to the binding agent.
 36. The method as recitedin claim 33 further comprising providing a second application of thebinding agent to the unembossed, continuous areas for reinforcement. 37.The method as recited in claim 36 wherein the second application ofbinding agent is performed by spraying or imprinting onto theunembossed, continuous areas.
 38. The method as recited in claim 36wherein the second application of binding agent is applied to both sidesof the unembossed, continuous areas.
 39. A device for implementing themethod as recited in claim 32 comprising: at least two embossing rollersmeshing with one another so that the non-woven fabric may be passedbetween them and shaped, the embossing rollers including toothed wheelssituated on a shaft and being separated from one another by spacers. 40.The device as recited in claim 39 wherein the toothed wheels havestraight or oblique teeth.
 41. The device as recited in claim 39 whereinthe toothed wheels of embossing rollers are made of iron, copper,aluminum, or alloys thereof or of polymers.
 42. The device as recited inclaim 39 wherein the toothed wheel of one of the embossing rollers ismade of aluminum and the toothed wheel of an other of the embossingrollers is made of polyamide.
 43. The device as recited in claim 39wherein only one embossing roller is heated.
 44. The device as recitedin claim 39 wherein a thermal radiator is provided for the heating.